The Heimlich maneuver was developed and introduced by Dr. Henry Heimlich, in 1974?
1. True
2. False

He is credited with it although there are doubts.
Dr. [ Henry Jay Heimlich (born Henry Judah Heimlich; February 3, 1920) is an American physician who has received credit as the inventor of abdominal thrusts, more commonly known as the Heimlich maneuver, though debate continues over his role in the development of the procedure.
In 2003, Heimlich's colleague Dr. Edward Patrick issued a

press-release portraying himself as the uncredited co-developer of the maneuver.[11][12] "'I would like to get proper credit for what I've done...but I'm not hyper about it.'"
]

You choose a marble at random from a bag containing eight brown marbles, six yellow marbles, and one purple marble. You replace the marble and then choose again. The chance of getting both yellow is 4/25.6/15*6/15 = 36/225 = 4/25